SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb1d599fbd3b678845836cbfd0f23a511c47a0366c9406a1d2c30a5d4c46448b' 
  AND token = 'ZvpXWeRYvt7PAnR1+APCgBx15q1fUpbPYhoaesAzjHM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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