SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1da6ff29419170b50efde2636f38bb1f1eee05a12a7470c3896196dbd3e7486' 
  AND token = 'yeQZCtNf3lbTOifPaFcDUPjmuUsgf6gqskGcky7Bmtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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