SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7ac07066494792ced979948e1143f02ce6b3b2ee865d6b2e11d3a09bab2954e' 
  AND token = 'sExUJP55jR0Vg3jIVaLFvFh1xjdLMKjH7HApVCRkAME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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