SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb6f64fb6fe4cc941f15a749a8619aa2b58eed38d130f6469ab9fd83adb66b1' 
  AND token = 'bTzhDs+slqwAVrsKLiMgC7ct2HFFbD/p9LmviuGaEms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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