SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d04f8f4a2d93783a0ffa6d0d4be05103654dc9c0176e68cbf7b5e2b00e00883' 
  AND token = 'U3ElhjYo5LAKr4S2jhteN37KUl7G4TuT6UioMEmKaYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}