SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3a832698a98404a7671ddbc1bbde10dfacc3ad442356c25cd7dfa9e69fdd0b0' 
  AND token = 'tLf0JYMUgO5qE/zsNF+lpf3B2gN5pfo5WoUYIZAwChY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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