SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff5fcb337c163ddd01ca0c2a4904b88a309025c993c23c727c77265ff2e48f01' 
  AND token = 'OplrM/rjifjbtSIt4WF/KTnRO7Yj7WRcXAM8Jb07tpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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