SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5b3a639206fbf743a4a8156fd7b89a5abf8a6168c51c1a1d2a11c64634dcec0' 
  AND token = 'hP7B0IWwEYABCMu1volSwyxz0oJ9/lp3PXOJe22iEYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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