SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f27938e8c06649be158ae41c1b407d7f812b6b73ee35c8aff4c5443890207ca9' 
  AND token = 'mM6fB5EVf+hYMlDurd02PYldI4gjZHGhS78wLcTC9HA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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