SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2301998d2024e5fa24d6c2af29e995071513528fdbca839b7fb4826040eeaad' 
  AND token = 'pCHEDZ2KYYl5gQAaJf+48RmO+vpcr7wGLnc88gq5Pms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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