SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52c2ac3ee91c30328efb4dc359550011e16a040afeadbae93d486d4039f8d095' 
  AND token = 'Dpxk23ENKJceMGkr3AZpFEtqbeVL39Y+hu9DZszfJIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}