SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4206e23c377443fc2400c6d2884e2c0791f1917aeed49e5c092e5f274c040b1' 
  AND token = '74XVgeu/k3OUsj0e5yl0bXbgD7ow1pnmH+j8FP8dZkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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